Fall is an especially good time to plant perennials because the seasonal conditions – soil temperature, cooler air, and less sunlight – all encourage strong root growth. The downside to fall planting is that many plants, their blooming period in the past, are heading into dormancy. Ephemerals that bloomed in spring are completely dormant, and the early summer bloomers look sleepy, as they prepare for winter ahead. It is a good time to plant, but not the most visually rewarding.
In the fall, the amount of top-growth that occurs on newly installed transplants is typically pretty minimal. Instead, most of the action is taking place underground. Timing is important for fall-planted perennials because the roots need to become established before winter sets in. Ideally, fall transplants should be in the ground at least six weeks before the ground freezes. Frost is not a serious issue for hardy perennials. It may stop the growth of the plant above the ground, but the roots will continue to grow until the ground is frozen. While frost itself is not an issue, frost heave can cause problems. Frost heave occurs when the ground freezes and then thaws once, or repeatedly. These freeze-thaw events can cause new transplants to rise up out of the ground if the roots are not sufficiently anchored in the soil. Six weeks allows enough time for the roots to become anchored and minimizes the chance of ‘frost heave.’
Because of the natural cycle of the hardy perennials, there can be a significant difference in appearance between a spring shipment and a fall shipment of plants. Spring shipped plants are in a strong top-growth phase, rushing to meet and fulfill their destiny. In a fall shipment, the hardy perennial natives are approaching a dormant phase. Plants can range from being fully leafed out and blooming (Aster & Goldenrods), to being completely dormant with no growth showing (spring ephemerals). The plants in your shipment may be cut-back, as well. It can be a surprise to open a shipment of dormant and/or cut-back plants, but rest assured, the plants you receive from us are alive with viable root systems, and ready to spring to life when their time arrives. Proceed to Install your plants with care as if they were the healthiest plants in the world – because they are!
Further reading on our website:
Read Tips for Planting Perennials in Fall before tucking your plants in for the winter.
Learn How to Transplant Bare Root Plants, for spring ephemerals, shipped in a bare root format.